PPI, Retina displays, and what makes a screen ‘good’

Retina PPIIf you’ve read any reviews recently about phones, tablets, and other gizmos, you’ve probably come across a lot of talk of PPI (Pixels Per Inch) and “Retina” screens.

In short, the number of pixels crammed into a device’s screen seems to be uber-important to which gizmos get the best reviews.

But hang on a minute… Just what do these numbers mean?

Does it really matter that much?

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